Methods of forming a metal telluride material, related methods of forming a semiconductor device structure, and related semiconductor device structures

ABSTRACT

Accordingly, a method of forming a metal chalcogenide material may comprise introducing at least one metal precursor and at least one chalcogen precursor into a chamber comprising a substrate, the at least one metal precursor comprising an amine or imine compound of an alkali metal, an alkaline earth metal, a transition metal, a post-transition metal, or a metalloid, and the at least one chalcogen precursor comprising a hydride, alkyl, or aryl compound of sulfur, selenium, or tellurium. The at least one metal precursor and the at least one chalcogen precursor may be reacted to form a metal chalcogenide material over the substrate. A method of forming a metal telluride material, a method of forming a semiconductor device structure, and a semiconductor device structure are also described.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/556,751, filed Jul. 24, 2012, now U.S. Pat. No. 8,741,688, issuedJun. 3, 2014, the disclosure of which is hereby incorporated herein inits entirety by this reference.

FIELD

The disclosure, in various embodiments, relates generally to the fieldof semiconductor device design and fabrication. More specifically, thedisclosure relates to methods of forming a metal chalcogenide material,to related methods of forming a semiconductor device structure, and to arelated semiconductor device structure.

BACKGROUND

Over the past few decades, there has been interest in chalcogenidematerials for use in semiconductor devices, such as non-volatilememories, solar cells, photodetectors, or electroconductive electrodes.For example, chalcogenide materials have been used in phase changerandom access memory devices. Chalcogenide materials are capable ofstably transitioning between physical states (e.g., amorphous,semi-amorphous, and crystalline states) upon the application of aphysical signal (e.g., a high current pulse, or a low current pulse).Each physical state can exhibit a particular resistance that may be usedto distinguish logic values of a phase change memory random accessmemory cell.

One of the current difficulties associated with the use of chalcogenidematerials in semiconductor device structures is the formation of thematerial. Chalcogenide materials have been formed by physical vapordeposition (PVD), chemical vapor deposition (CVD), and atomic layerdeposition (ALD). PVD and CVD processes lack the conformality needed touniformly deposit material on a substrate, as integrated circuit scalingapproaches less than or equal to 10 nanometers (nm). In addition, due tothe equipment and targets needed, PVD processes can be expensive. ALDprocesses have been used to form chalcogenide materials by reactingalkyl tellurides and alkyl selenides with volatile, pyrophoric, alkylreactants to form metal tellurides or metal selenides. For example,alkyl tellurides have been reacted with dimethylcadmium to form cadiumtelluride through ALD processes. However, ALD processes for formingchalcogenide materials are limited by the availability (e.g., volatilealkyl compounds suitable for reaction with tellurium compounds in ALDprocesses do not exist for many for many metals), reactivity, andtoxicity of appropriate ALD precursors.

It would be desirable to be able to form additional chalcogenidematerials using ALD processes. It would be further desirable ifchalcogenide materials formed using the ALD processes exhibited highpurity, and if any precursors used in the formation of the chalcogenidematerials were readily available, less toxic, and non-pyrophoric.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a partial cross-sectional view of a semiconductordevice structure, in accordance with an embodiment of the disclosure;

FIG. 2 is an x-ray photoelectron spectroscopy (XPS) depth profile for azirconium telluride material formed using an embodiment of thedisclosure, as described below in Example 2;

FIG. 3 is a scanning electron micrograph (SEM) of a zirconium telluridematerial formed using an embodiment of the disclosure, as describedbelow in Example 3;

FIG. 4 is an atomic force microscopy (AFM) image of a zirconiumtelluride material formed using an embodiment of the disclosure, asdescribed below in Example 3; and

FIG. 5 is an x-ray diffraction (XRD) diagram of a zirconium telluridematerial formed using an embodiment of the disclosure, as describedbelow in Example 5.

DETAILED DESCRIPTION

Methods of forming a metal chalcogenide material by atomic layerdeposition (ALD) are disclosed, as are related methods of formingsemiconductor device structures including the metal chalcogenidematerial, and related semiconductor device structures. As used herein,the term “atomic layer deposition” or “ALD” means and includes a vapordeposition process in which a plurality of separate deposition cyclesare conducted in a chamber. ALD includes, but is not limited to, atomiclayer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE,organometallic MBE, and chemical beam epitaxy when performed withalternating pulses of precursors and purge (i.e., inert) gas. In someembodiments, during each deposition cycle of the ALD process of thedisclosure, metal precursors, each including one of an amine ligand andan imine ligand, may be chemisorbed to a substrate in a chamber, excessmetal precursors may be purged out of the chamber, chalcogen precursors(e.g., tellurium-containing compounds, selenium-containing compounds, orsulfur-containing compounds) may be introduced into the chamber to reactwith the chemisorbed metal precursors, and excess precursors andbyproducts may be removed from the chamber. In additional embodiments,the deposition order of the metal precursors and the chalcogenprecursors may be reversed. By repeating the deposition and purge acts,the metal chalcogenide material is formed by ALD. The metal chalcogenidematerial may exhibit minimal oxygen, carbon, or nitrogen impurities, ifany. The metal chalcogenide material may be used as a thin film for asemiconductor device structure, such as a photovoltaic device structure,a memory device structure (e.g., a phase change random access memorycell, a resistive random access memory cell, etc.), or an electronicswitch. The methods disclosed herein may facilitate excellentperformance and stability in semiconductor device structures (e.g.,memory cells, photovoltaic device structures, etc.) and semiconductordevices (e.g., memory devices, photovoltaic devices, etc.) including ametal chalcogenide material.

The following description provides specific details, such as materialtypes and processing conditions, in order to provide a thoroughdescription of embodiments of the present disclosure. However, a personof ordinary skill in the art would understand that the embodiments ofthe present disclosure may be practiced without employing these specificdetails. Indeed, the embodiments of the present disclosure may bepracticed in conjunction with conventional semiconductor fabricationtechniques employed in the industry. In addition, the descriptionprovided below does not form a complete process flow for manufacturing asemiconductor device. The semiconductor device structures describedbelow do not form a complete semiconductor device. Only those processacts and structures necessary to understand the embodiments of thepresent disclosure are described in detail below. Additional acts toform a complete semiconductor device from the semiconductor devicestructures may be performed by conventional fabrication techniques. Alsonote, any drawings presented herein are for illustrative purposes only,and are thus not drawn to scale. Additionally, elements common betweenfigures may retain the same numerical designation.

FIG. 1 is simplified partial cross-sectional view illustrating asemiconductor device structure 100 formed using an embodiment of themethod of the disclosure. The semiconductor device structure 100 mayinclude a substrate 102 and a metal chalcogenide material 104. The metalchalcogenide material 104 may be formed on or over the substrate 102. Asused herein, the term “substrate” means and includes a base material orconstruction upon which additional materials are formed. The substrate102 may be a semiconductor substrate, a base semiconductor layer on asupporting structure, a metal electrode, or a semiconductor substratehaving one or more materials, structures, or regions formed thereon.Previous process acts may have been conducted to form materials,regions, or junctions in the base semiconductor structure or foundation.The substrate 102 may be a conventional silicon substrate or other bulksubstrate comprising a layer of semiconductive material. As used herein,the term “bulk substrate” means and includes not only silicon wafers,but also silicon-on-insulator (SOI) substrates, such assilicon-on-sapphire (SOS) substrates and silicon-on-glass (SOG)substrates, epitaxial layers of silicon on a base semiconductorfoundation, and other semiconductor or optoelectronic materials, such assilicon-germanium, germanium, gallium arsenide, gallium nitride, andindium phosphide. The substrate 102 may be doped or undoped. By way ofnon-limiting example, the substrate 102 may be silicon, silicon dioxide,silicon with native oxide, silicon nitride, glass, semiconductor, metaloxide, metal, a titanium nitride (TiN), tantalum (Ta), a tantalumnitride (TaN), niobium (Nb), a niobium nitride (NbN), a molybdenumnitride (MoN), molybdenum (Mo), tungsten (W), a tungsten nitride (WN),copper (Cu), cobalt (Co), nickel (Ni), iron (Fe), aluminum (Al), or anoble metal.

The metal chalcogenide material 104 includes at least one metalchalcogenide compound including a chalcogen (e.g., tellurium, selenium,or sulfur) bonded to at least one metal. As used herein, the term“metal” means and includes an alkali metal, an alkaline earth metal, atransition metal (e.g., titanium, zirconium, hafnium, vanadium, niobium,tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt,nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, etc.),a post-transition metal (e.g., aluminum, gallium, indium, tin, lead,bismuth, etc.), or a metalloid (e.g., boron, silicon, germanium,arsenic, antimony, etc.). The metal chalcogenide material 104 mayinclude a single metal chalcogenide compound species or may includemultiple metal chalcogenide compound species. In some embodiments, themetal chalcogenide material 104 includes microsegregated areas of themetal and the chalcogen. In additional embodiments, the metalchalcogenide material 104 includes a greater proportion of the metalrelative to the chalcogen, and may be characterized as “rich” in themetal.

By way of non-limiting example, the metal chalcogenide material 104 maybe formed of and include zirconium telluride (ZrTe_(x)), coppertelluride (CuTe_(x)), silver telluride (AgTe_(x)), gold telluride(AuTe_(x)), zinc telluride (ZnTe_(x)), aluminum telluride (AlTe_(x)),gallium telluride (GaTe_(x)), indium telluride (InTe_(x)), tin telluride(SnTe_(x)), bismuth telluride (BiTe_(x)), germanium telluride(GeTe_(x)), arsenic telluride (ArTe_(x)), antimony telluride (SbTe_(x)),zirconium selenide (ZrSe_(x)), copper selenide (CuSe_(x)), silverselenide (AgSe_(x)), gold selenide (AuSe_(x)), zinc selenide (ZnSe_(x)),aluminum selenide (AlSe_(x)), gallium selenide (GaSe_(x)), indiumselenide (InSe_(x)), tin selenide (SnSe_(x)), bismuth selenide(BiSe_(x)), germanium selenide (GeSe_(x)), arsenic selenide (ArSe_(x)),antimony selenide (SbSe_(x)), bismuth selenide (BiSe_(x)), zirconiumsulfide (ZrS_(x)), copper sulfide (CuS_(x)), silver sulfide (AgS_(x)),gold sulfide (AuS_(x)), zinc sulfide (ZnS_(x)), bismuth sulfide(BiS_(x)), indium sulfide (InS_(x)), or antimony sulfide (SbS_(x)). Insome embodiments, the metal chalcogenide material is formed of andincludes zirconium telluride (ZrTe_(x)). Formulae including “x” above(e.g., ZrTe_(x), CuTe_(x), AgTe_(x), AuTe_(x), ZnTe_(x), etc.) representa composition that on average contains x atoms of chalcogen for everyone atom of the metal component. As the formulae are representative ofrelative atomic ratios and not strict chemical formula, the metalchalcogenide material 104 may be stoichiometric or non-stoichiometric,and values of x may be integer or may be non-integer. As used herein,the term “non-stoichiometric” means and includes an elementalcomposition that cannot be represented by a ratio of well-definednatural numbers and is in violation of the law of definite proportions.

While the metal chalcogenide material 104 is described above asincluding at least one binary compound, the metal chalcogenide material104 may also be formed of and include at least one multinary compound,such as a ternary compound or a quaternary compound. If metalchalcogenide material 104 includes a multinary compound, the metalchalcogenide material 104 may include at least one additional element,such as another alkali metal, alkaline earth metal, transition metal,post-transition metal, or metalloid. The additional element may include,but is not limited to, titanium (Ti), zirconium (Zr), hafnium (Hf),vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum(Mo), tungsten (W), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni),palladium (Pd), platinum (Pd), copper (Cu), silver (Ag), gold (Au), zinc(Zn), cadmium (Cd), aluminum (Al), gallium (Ga), indium (In), tin (Sn),lead (Pb), bismuth (Bi), boron (B), silicon (Si), germanium (Ge),arsenic (As), or antimony (Sb). The additional element may also be anon-metal element(s), such as nitrogen (N), oxygen (O), or phosphorus(P). The additional element(s) may affect the properties of the metalchalcogenide material 104, such as the ability to form the metalchalcogenide material 104 in a crystalline form or an amorphous form.The additional element(s) may be selected to be compatible with thechalcogen and the metal during the ALD process. In additionalembodiments, the metal chalcogenide material 104 may be formed of amixture of at least one binary compound and at least one multinarycompound.

The metal chalcogenide material 104 may be formed conformally on or oversubstrate 102 and features thereof, and may be amorphous or crystallineas formed. A thickness of the metal chalcogenide material 104 and apressure within a reaction chamber used to form metal chalcogenidematerial 104 may at least partially control the phase state (e.g.,amorphous, semi-amorphous, or crystalline) of the metal chalcogenidematerial 104. For example, at thicknesses of from about 200 Angstroms(Å) or less, the metal chalcogenide material 104 may be amorphous asformed. If the metal chalcogenide material 104 is amorphous as formed,the metal chalcogenide material 104 may be smooth, uniform, andcontinuous. As a non-limiting example, if the metal chalcogenidematerial 104 is formed of and includes amorphous ZrTe_(x), the metalchalcogenide material 104 may have a root mean square (RMS) of less thanor equal to about 2.0 nanometers (nm), such as less than or equal toabout 1.6 nanometers, when measured by atomic force microscopy (AFM). Ifthe metal chalcogenide material 104 is crystalline as formed, thechalcogenide material 104 may be rougher, but may exhibit one or moreproperties desirable for an intended application. As a non-limitingexample, if the metal chalcogenide material 104 is formed of andincludes crystalline ZrTe_(x) (e.g., monoclinic ZrTe₃), the chalcogenidematerial 104 may exhibit a resistivity of about 400 μOhm·cm. Impuritiessuch as carbon, oxygen, and nitrogen may be substantially absent fromthe metal chalcogenide material 104 (i.e., the metal chalcogenidematerial 104 may include less than or equal to about 1 atomic percent ofcarbon, oxygen, and nitrogen impurities).

Accordingly, a semiconductor device structure of the disclosure maycomprise a zirconium telluride material on a substrate, the zirconiumtelluride material substantially free of oxygen, nitrogen, and carbon.

The metal chalcogenide material 104 may be formed on or over thesubstrate 102 using an ALD process. The ALD process may includeconducting alternating pulses of at least one metal precursor and atleast one chalcogen precursor, with intervening pulses of an inert gas.The inert gas may be nitrogen (N₂), argon (Ar), helium (He), neon (Ne),krypton (Kr), xenon (Xe), or other gases that, although not inert,behave as inert under the conditions of the deposition of theprecursors. The metal precursor may function as a source of metal forthe metal chalcogenide material 104. A single metal precursor speciesmay be included in a particular pulse, or multiple metal precursorspecies may be included in a particular pulse. The chalcogen precursormay function as a source of chalcogen for the metal chalcogenidematerial 104. The precursors (i.e., the metal precursor and thechalcogen precursor) may be in a solid, liquid, or gaseous form at roomtemperature and atmospheric pressure. If the precursors are in a solidor liquid form at room temperature and atmospheric pressure, theprecursors may be vaporized before introduction into a chamber holdingthe substrate 102. Vaporization of the precursors may be accomplished byconventional techniques, which are not described in detail herein. Theprecursors may be commercially available or synthesized by conventionaltechniques.

The metal precursor may be an organometallic compound including acomplex of metal (e.g., Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co,Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Si, Ge, Sn, Pb, As, Sb,Bi, or a combination thereof) and at least one ligand. In someembodiments, the metal is Zr. The ligand may be one of an amine groupand an imine group, having the chemical formulas R¹R²N⁻ and R¹R²C═N⁻,respectively, where each of R¹ and R² is independently hydrogen, or anorganic group having between one carbon atom and ten carbon atoms. Asuitable organic group may be, for example, an alkyl group or an arylgroup. The alkyl group may be saturated or unsaturated, linear orbranched, and may include heteroatoms, such as oxygen, nitrogen, orsulfur. Thus, each of R¹ and R² may independently be an alkenyl,alkynyl, or alkoxide group. The aryl group may be a phenyl group, asubstituted phenyl group, or a heteroatom-containing group, such as anitrogen-containing group or a sulfur-containing group. In someembodiments, the ligand is dimethylamino. In some embodiments, the metalprecursor is tetrakis(dimethylamino)zirconium (TDMAZ).

The chalcogen precursor may be a hydride compound of the chalcogen, analkyl compound of the chalcogen, or an aryl compound of the chalcogen,such as an alkyl compound of tellurium (Te), selenium (Se), or sulfur(S). The chalcogen precursor may have the chemical formula Te(R³R⁴) orSe(R³R⁴), where each of R³ and R⁴ is independently H, or an organicgroup having between one carbon atom and ten carbon atoms. A suitableorganic group may be, for example, an alkyl group or an aryl group. Thealkyl group may be saturated or unsaturated, linear or branched, and mayinclude heteroaroms, such as oxygen, nitrogen, or sulfur. Thus, each ofR³ and R⁴ may be an alkenyl, alkynyl, or alkoxide group. The aryl groupmay be a phenyl group, a substituted phenyl group, or aheteroatom-containing group, such as a nitrogen-containing group or asulfur-containing group. Each of R³ and R⁴ may be independently selectedso that the chalcogen precursor exhibits desired properties, such asreactivity, volatility, and toxicity, for use in the ALD process. As anon-limiting example, the chalcogen precursor may be hydrogen telluride;a dialkyl telluride, such as diemethyl telluride, diethyl telluride,diisopropyl telluride, dibutyl telluride, or bis(t-butyl) telluride; adiaryl telluride; an alkyl tellurane, such as ethyl tellurane; or anaryl tellurane. In some embodiments, the chalcogen precursor isbis(t-butyl) telluride. The metal precursor and the chalcogen precursormay be selected to exhibit sufficient reactivity with one another toform the metal chalcogenide material 104 on the substrate 102.

Selection of the chalcogen precursor may depend on the temperature atwhich the ALD process is to be conducted. By way of non-limitingexample, an alkyl compound may be used when the ALD process is to beconducted at a temperature of from about 20° C. to about 400° C., suchas from about 150° C. to about 350° C. In addition to reactivity andvolatility considerations, the temperature at which the ALD process isconducted may depend on the thermal budget of the semiconductor devicestructure 100 in which the metal chalcogenide material 104 is to beused. To prevent damage to other components of the semiconductor devicestructure 100, the other components formed on, in, or over the substrate102 should be compatible with the conditions of the ALD process.

To form the metal chalcogenide material 104, the precursors (i.e., theat least one metal precursor and the at least one chalcogen precursor)may be vaporized and sequentially deposited/chemisorbed on or over thesubstrate 102. As used herein, the terms “chemisorb” and “chemisorption”mean and include a mechanism wherein at least one of the precursors isadsorbed or bound to at least one surface of another material, such as asurface of the substrate 102, by way of chemical bonding, such ascovalent bonding or ionic bonding. A first of the precursors isintroduced to the substrate 102 under conditions that enable metal fromthe metal precursor or chalcogen from the chalcogen precursor to reactwith at least one surface of the substrate 102, forming a chemisorbedmonolayer of the metal precursor or the chalcogen precursor thereon.Excess of the first of the precursors may be removed, and a second ofthe precursors (e.g., the chalcogen precursor if the first of theprecursors is the metal precursor, or the metal precursor if the firstof the precursors is the chalcogen precursor) is introduced to andreacted with the chemisorbed monolayer of the first of the precursors toform the metal chalcogenide material 104. Excess of the second of theprecursors may be removed and, if desired, the above deposition cycle ofthe ALD process may be repeated to achieve a desired thickness of themetal chalcogenide material 104. The metal of the metal precursor andthe chalcogen of the chalcogen precursor function as reactants for eachother and eliminate nitrogen-containing groups (e.g., amine groups, orimine groups) during the ALD process. No additional reaction gases areutilized to form the metal chalcogenide material 104. By appropriatelyselecting the reactivities of the metal precursor and the chalcogenprecursor, the reaction of the metal precursor and the chalcogenprecursor is thermodynamically favorable. Since the reaction isthermodynamically favorable, the reaction may proceed to completion,enabling the metal chalcogenide material 104 to be formed with minimalamounts of impurities, such as minimal amounts of carbon, nitrogen, andoxygen, if any. Consequently, the metal chalcogenide material 104 may begreater than or equal to about 99 percent pure.

Accordingly, a method of forming a metal telluride material may comprisereacting at least one metal amine compound with at least onetellurium-containing compound to form a metal telluride material on asubstrate.

Furthermore, a method of forming a semiconductor device structure maycomprise forming a zirconium telluride material on a substrate by atomiclayer deposition.

The formation of the metal chalcogenide material 104 through an ALDprocess utilizing a chalcogen precursor (e.g., bis(t-butyl)tellurium)and a metal precursor including a complex of metal and amine group(s)(e.g., tetrakis(dimethylamino)zirconium) was unexpected. In addition,the purity of the metal chalcogenide material 104 was also unexpected.That is, upon the unexpected formation of the metal chalcogenidematerial 104, it was believed that the metal chalcogenide material 104would exhibit carbon, nitrogen, and/or oxygen impurities (i.e.,concentrations of carbon, nitrogen, and/or oxygen accounting for greaterthan 1 atomic percent of the metal chalcogenide material 104).Consequently, the purity of the metal chalcogenide material 104 formedusing embodiments of the methods of the disclosure was unexpected.

In some embodiments, a work piece (not shown) such as a carrier to whichthe substrate 102 is mounted may be placed into (or remain in fromprevious processing) a chamber (not shown). The chamber may be aconventional ALD reactor, examples of which are known in the art and,therefore, are not described in detail herein. The metal precursor maybe introduced into the chamber and may chemisorb to a surface of thesubstrate 102. For the sake of simplicity, the precursors (i.e., themetal precursor and the chalcogen precursor) are described as beingexposed to the substrate 102 in a particular order. However, theprecursors may be exposed to the substrate 102 in any order. The metalprecursor may be of sufficient volatility and reactivity to react withthe surface of the substrate 102. The metal precursor may be introducedinto the chamber with an inert gas (e.g., He) to form a mixture of themetal precursor and the inert gas. The metal precursor may be introducedinto the chamber for an amount of time sufficient for the reaction tooccur, such as from about 0.1 second to about 30 seconds. The metalprecursor may be introduced into the chamber at a flow rate of betweenabout 1 sccm and about 100 sccm, a temperature of between about 20° C.and about 400° C., and a pressure of between about 0.0005 Torr and about1 Torr. A monolayer (not shown) of the metal precursor may be formed onthe surface of the substrate 102 as a result of the chemisorption on thesurface of substrate 102. The monolayer formed by chemisorption of themetal precursor may be self-terminating since a surface of the monolayermay be non-reactive with the metal precursor used in forming themonolayer.

Subsequent pulsing with inert gas removes excess metal precursor (i.e.,metal precursor not chemisorbed to the surface of the substrate 102)from the chamber. Purging the chamber also removes volatile byproductsproduced during the ALD process. The inert gas may be introduced intothe chamber, for example, for from about 5 seconds to about 120 seconds.After purging, the chamber may be evacuated, or “pumped,” to removegases, such as the excess metal precursor or the volatile byproducts.For example, the excess metal precursor may be purged from the chamberby techniques including, but not limited to, contacting the substrate102 with the inert gas and/or lowering the pressure in the chamber tobelow the deposition pressure of the metal precursor to reduce aconcentration of the metal precursor contacting the substrate 102 and/orchemisorbed metal precursor. A suitable amount of purging to remove theexcess metal precursor and the volatile byproducts may be determinedexperimentally, as known to those of ordinary skill in the art. The pumpand purge sequences may be repeated multiple times.

After purging, the chalcogen precursor may be introduced into thechamber and may chemisorb to exposed surfaces of the monolayer of metalprecursor. The chalcogen precursor may be of sufficient volatility andreactivity to react with the chemisorbed metal precursor. The chalcogenprecursor may be introduced into the chamber for an amount of timesufficient for the reaction to occur, such as from about 0.1 second toabout 30 seconds. For example, the chalcogen precursor may be introducedinto the chamber at a flow rate of between about 1 sccm and about 100sccm, a temperature of between about 20° C. and about 400° C., and apressure of between about 0.0005 Torr and about 1 Torr Reactionbyproducts and the excess chalcogen precursor may be removed from thechamber utilizing the pump and purge cycle as described above. Thechalcogen formation and purging may be repeated any number of times toform a monolayer of chalcogen on the chemisorbed metal. The chalcogenformation and purging may be, for example, repeated in sequence fromabout two times to about five times to form the monolayer of chalcogenof a desired thickness.

Accordingly, a method of forming a metal chalcogenide material maycomprise contacting a substrate with at least one metal precursor and atleast one chalcogen precursor, the at least one metal precursorcomprising an amine or imine compound of an alkali metal, an alkalineearth metal, a transition metal, a post-transition metal, or ametalloid, and the at least one chalcogen precursor comprising ahydride, alkyl, or aryl compound of sulfur, selenium, or tellurium. Theat least one metal precursor and the at least one chalcogen precursormay be reacted to form a metal chalcogenide material over the substrate.

In additional embodiments, at least one other material (not shown) maybe located on or over the metal chalcogenide material 104. The othermaterial may, for example, be a conductive material such as one or moreof W, Ni, WN, TiN, TaN, polysilicon, and a metal silicide (e.g.,WSi_(y), TiSi_(y), CoSi_(y), TaSi_(y), MnSi_(y), where y is a rationalnumber greater than zero). The other material may be formed of andinclude the same material or a different material than the substrate102. The other material may be formed using known techniques, such asPVD, CVD, or ALD, which are not described in detail herein.

The semiconductor device structure 100 including the metal chalcogenmaterial 104 may be used in a wide variety of semiconductor devicesincluding, but not limited to, photovoltaic devices, and memory devices(e.g., non-volatile memory devices, such as resistive random accessmemory devices, etc.). Photovoltaic devices may, for example, be used insolar panel devices for power generation. Memory devices may, forexample, be used in wireless devices, personal computers, or otherelectronic devices.

By forming the metal chalcogenide material 104 according to the methodsof the disclosure, a highly conformal and substantially pure metalchalcogenide material may be produced. The purity of the metalchalcogenide material may facilitate the formation of semiconductordevice structures and semiconductor devices exhibiting excellentperformance and stability. In addition, the metal chalcogenide material104 may be formed from the metal precursors and chalogen precursorswithout the use of other reactants (e.g., reaction gases), therebyreducing process costs and increasing process efficiency. Further more,the methods of the disclosure utilize non-pyrophoric reactants thatsubstantially reduce handling and disposal concerns relative toconventional methodologies.

The following example serves to explain embodiments of the disclosure inmore detail. This example is not to be construed as being exhaustive orexclusive as to the scope of the disclosure. While Example 1 describesforming zirconium telluride as the metal chalcogenide material, othermetal chalcogenide materials may be formed in a similar manner byappropriately selecting the metal precursor and the chalcogen precursor,as previously described above.

Example 1 ALD Process for Forming Zirconium Telluride

Zirconium telluride was produced by an ALD process usingtetrakis(dimethylamino)zirconium (TDMAZ) and bis(t-butyl)telluride. Asilicon oxide substrate was provided on a chuck within a reactionchamber. The chuck was brought to a temperature of 300° C. The pressurewithin the reaction chamber was about 5×10⁻⁴ Torr. Solid TDMAZ washeated to a temperature of about 62° C. to form liquid TDMAZ and wasthen introduced into the reaction chamber in He gas (20 sccm) for aboutfive seconds. After purging with He gas for 20 seconds, thebis(t-butyl)telluride was introduced for about two seconds. The reactionchamber was then purged again with He gas for 20 seconds. The ALDprocess resulted in a zirconium telluride growth rate of about 0.9Angstroms per cycle.

Example 2 Purity Analysis

Following 300 cycles of the ALD process described in Example 1, theresulting zirconium telluride material was analyzed using x-rayphotoelectron spectroscopy (XPS). The XPS depth profile for thezirconium telluride material is shown in FIG. 2. FIG. 2 demonstratesthat the zirconium telluride material was highly pure, exhibiting nodetectable carbon, nitrogen, or oxygen impurities.

Example 3 Smoothness Analysis

A 65 Angstrom (Å) thick zirconium telluride material formed on a siliconnitride substrate by the ALD process described in Example 1 wassubjected to smoothness analysis. FIG. 3 is a scanning electronmicrograph (SEM) showing a perspective view of the zirconium telluridematerial on the silicon nitride substrate. As shown in FIG. 3, thezirconium telluride material was substantially smooth. FIG. 4 is anatomic force microscopy (AFM) image illustrating that the zirconiumtelluride material exhibited an RMS of about 1.6 nm, and an averageroughness of about 1.2 nm.

Example 4 Tape Test

A 65 Å thick zirconium telluride material formed by the ALD processdescribed in Example 1 was subjected to a tape test. A “#” mark wasscribed into the center of the zirconium telluride material and a stripof tape was pressed onto the zirconium telluride material and quicklypeeled off. No peeling of the zirconium telluride material wasexhibited.

Example 5 Morphology Analysis

A 65 Å thick zirconium telluride material formed by the ALD processdescribed in Example 1 was subjected to morphology analysis. FIG. 5 isan x-ray diffraction (XRD) diagram of the zirconium telluride material.FIG. 5 demonstrates that the zirconium telluride material was amorphousas deposited.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and have been described in detail herein.However, the disclosure is not intended to be limited to the particularforms disclosed. Rather, the disclosure is to cover all modifications,equivalents, and alternatives falling within the scope of the followingappended claims and their legal equivalents.

What is claimed is:
 1. A method of forming a metal telluride material,comprising: reacting at least one zirconium amine compound with at leastone tellurium-containing compound to form a zirconium telluride materialchemisorbed on a surface of a substrate, the zirconium telluridematerial substantially free of oxygen, nitrogen, and carbon.
 2. Themethod of claim 1, wherein reacting at least one zirconium aminecompound with at least one tellurium-containing compound comprisesreacting tetrakis(diemethylamino)zirconium chemisorbed on the surface ofthe substrate with at least one tellurium alkyl compound to form thezirconium telluride material.
 3. The method of claim 2, wherein reactingtetrakis(diemethylamino)zirconium with at least one tellurium alkylcompound to form a zirconium telluride material comprises reactingtetrakis(diemethylamino)zirconium with bis(t-butyl)telluride.
 4. Themethod of claim 1, wherein reacting at least one zirconium aminecompound with at least one tellurium-containing compound to form azirconium telluride material on the substrate comprises forming thezirconium telluride material by atomic layer deposition.
 5. The methodof claim 1, wherein reacting at least one zirconium amine compound withat least one tellurium-containing compound comprises: chemisorbing oneof the at least one zirconium amine compound and the at least onetellurium-containing compound to the surface of the substrate; andexposing the one of the at least one chemisorbed zirconium aminecompound and the at least one chemisorbed tellurium-containing compoundto the other of the at least one zirconium amine compound and the atleast one tellurium-containing compound.
 6. The method of claim 5,wherein chemisorbing one of the at least one zirconium amine compoundand the at least one tellurium-containing compound to the surface asurface of the substrate comprises forming a monolayer of the one of theat least one zirconium amine compound and the at least onetellurium-containing compound on the surface of the substrate.
 7. Amethod of forming a semiconductor device structure, comprising: forminga zirconium telluride material chemisorbed on a surface of a substrateby atomic layer deposition, the zirconium telluride materialsubstantially free of oxygen, nitrogen, and carbon.
 8. The method ofclaim 7, wherein forming a zirconium telluride material chemisorbed on asurface of a substrate by atomic layer deposition comprises: introducingat least one zirconium amine compound into a chamber having thesubstrate therein to chemisorb the at least one zirconium amine compoundto the surface of the substrate; and reacting at least onetellurium-containing compound with the at least one chemisorbedzirconium amine compound to form the zirconium telluride material. 9.The method of claim 8, wherein introducing at least one zirconium aminecompound into a chamber having the substrate therein comprisesintroducing tetrakis(dimethylamino)zirconium into the chamber.
 10. Themethod of claim 8, wherein introducing at least one zirconium aminecompound into a chamber having the substrate therein comprisesintroducing a complex of zirconium and a ligand having the chemicalformula R¹R²N⁻ into the chamber, wherein each of R¹ and R² isindependently hydrogen or an organic group having between one carbonatom and ten carbon atoms.
 11. The method of claim 8, wherein reactingat least one tellurium-containing compound with the at least onechemisorbed zirconium amine compound comprises reacting the chemisorbedzirconium amine compound with a tellurium precursor having the chemicalformula Te(R³R⁴), wherein each of R³ and R⁴ is independently hydrogen oran organic group having between one carbon atom and ten carbon atoms.12. The method of claim 7, wherein forming a zirconium telluridematerial chemisorbed on a surface of a substrate by atomic layerdeposition comprises: introducing at least one tellurium-containingcompound into a chamber having the substrate therein to chemisorb the atleast one tellurium-containing compound to the surface of the substrate;and reacting at least one zirconium amine compound with the at least onechemisorbed tellurium-containing compound to form the zirconiumtelluride material.
 13. A semiconductor device structure, comprising: azirconium telluride material chemisorbed on a surface of a substrate,the zirconium telluride material substantially free of oxygen, nitrogen,and carbon.
 14. The semiconductor device structure of claim 13, whereinthe zirconium telluride material has a purity of greater or equal toabout 99 percent.
 15. The semiconductor device structure of claim 13,wherein the zirconium telluride material consists of zirconium andtellurium.
 16. The semiconductor device structure of claim 13, whereinthe zirconium telluride material is amorphous.
 17. The semiconductordevice structure of claim 13, wherein the zirconium telluride materialcomprises a crystalline zirconium telluride material.
 18. Thesemiconductor device structure of claim 13, wherein the zirconiumtelluride material comprises monoclinic ZrTe₃.
 19. A semiconductordevice structure, comprising: a zirconium telluride material on asubstrate, the zirconium telluride material substantially free ofoxygen, nitrogen, and carbon, and exhibiting an RMS value of less thanor equal to about 2.0 nanometers when measured by atomic forcemicroscopy.